Bsf Block 1: Epithelium Histology (Miller)

Front 1

Epithelium has (a little, a lot) of extracellular matrix.

Back 1

a little

Front 2

Simple epithelium has ______ layer of cells. Stratified epithelium has ______ layer of cells.

Back 2

one, more than one

Front 3

The name classification of a stratified epithelium sample (multiple cell layers) is determined by what?

Back 3

the very first layer of cells (apical surface)

Front 4

Simple squamous cells are are joined by ___________ to form a sheet

Back 4

tight junctions

Front 5

Simple squamous epithelium lines these 4 body parts:

Back 5

1. endothelium (blood vessels) - gas/nutrient exchange
2. mesothelium (body cavities) - lubrication
3. bowman's capsule in the kidney - fluid exchange
4. alveoli in the lung - gas exchange

Front 6

A single layer of cube shaped cells is called ________ and comprises _______ and ________. It functions in ________.

Back 6

-simple cuboidal epithelium
-ducts of many glands
-kidney tubules
-functions in protection/secretion/absorption

Front 7

Long, rectangular cells with a centrally located nucleus is called ________ and functions in ________

Back 7

simple columnar epithelium; protection/secretion/absorption/transport

Front 8

Columnar epithelium is found in 7 places

Back 8

lining stomach
lining intestine
lining uterus/oviducts
lining small bronchi of lungs
lining parasinal sinus
ependymal cells of spinal cord
wall of large kidney ducts

Front 9

Simple columnar epithelium cells have specialized projections on the apical surface called

Back 9

1. microvilli
2. cilia

Front 10

Microvilli fxn:
cilia fxn:

Back 10

Microvilli - increase surface area for absorption
Cilia - move matter along cell surface

Front 11

The brush border is formed by _________ on the apical surface of simple columnar epithelium. The brush border is surrounded by the __________.

Back 11

microvilli, glycocalyx

Front 12

What is the basal lamina?

Back 12

the layer of extracellular matrix on which the epithelium sits. Oftentimes the epithelium sits right on connective tissue--so the point at which the connective tissue ends and the epithelium starts is the basal lamina.

Front 13

What is the basal cell layer of stratified squamous epithelium composed of?

Back 13

cuboidal-to-columnar cells

Front 14

As you move from the basal layer closer to the apical layer, cells tend to _________ in shape.

Back 14

flatten

Front 15

In stratified squamous epithelium, cells are joined by _____________.

Back 15

desmosomes

Front 16

What is the primary function of stratified squamous epithelium?

Back 16

provide a protective barrier

Front 17

Where are non-keratinized stratified squamous epithelial cells found?

Back 17

moist cavities (oral cavity, esophagus, vagina, etc)

Front 18

How are keratinized stratified squamous epithelial cells formed?

Back 18

the cells on the superficial layers of the stratified squamous epithelium die and their nucleus/cytoplasm is replaced with keratin

Front 19

Give the most common example of keratinized stratified squamous epithelium.

Back 19

The skin

Front 20

Stratified cuboidal epithelium has how many layers of cuboidal cells?

Back 20

two

Front 21

Stratified cuboidal epithelium is very rare...but where is it usually found?

Back 21

lining sweat glands

Front 22

Stratified columnar epithelium is extremely _________ and is found in the...

Back 22

rare, found in COnjunctivae of eye and lining the ducts of some large glands

Front 23

What is the cell morphology of stratified columnar epithelium?

Back 23

One cuboidal layer at the basal lamina and one columnar layer at the apical surface

Front 24

Where is transitional epithelium ONLY found?

Back 24

portions of the urinary system, lining the bladder, ureter and urethra

Front 25

What is the cell morphology of transitional epithelium?

Back 25

2 to 6 layers, basal layers are usually cuboidal but the apical layers variable--round when the bladder is empty and flat when the bladder is distended

Front 26

Cells of transitional epithelium are joined by ____________ and are sometimes __________.

Back 26

-desmosomes

-binucleated

Front 27

What is the function of transitional epithelium cells? What makes this function possible?

Back 27

to form a barrier between urine and the underlying tissue...possible because the apical cells of transitional epithelium have unique protective intracellular "plaque" structures

Front 28

How can you distinguish transitional epithelium from non-keratanized stratified squamous epithelium?

Back 28

transitional epithelium has some binucleated cells. cells in transitional epithelium are way rounder and closer together

Front 29

Pseudostratified columnar epithelium is composed of how many layers?

Back 29

only one layer attached to the basal lamina. "pseudostratified" because it appears as more than one layer

Front 30

Ciliated pseudostratified columnar epithelium is found where?

Back 30

many portions of the respiratory system (trachea, primary bronchi, nasal cavity)

Front 31

Pseudostratified columnar epithelium without cilia is found where?

Back 31

ducts of large glands, male urethra and epididymis

Front 32

Stereocilia are actually ___________ that increase the surface area of what cells?

Back 32

-microvilli

-pseudostratified columnar epithelium cells of the epididymis

Front 33

What are the functions of pseudostratified columnar epithelium?

Back 33

-protection
-motility
-sensory perception

Front 34

Where do glands originate from?

Back 34

epithelium that penetrates into the underlying connective tissue @ basal lamina

Front 35

What glands maintain contact with the apical surface epithelium via ducts?

Back 35

exocrine

Front 36

What glands secrete their contents into the bloodstream?

Back 36

endocrine

Front 37

What cells make the basal lamina?

Back 37

epithelial cells and connective tissue fibroblasts

Front 38

What are major protein components of the basal lamina?

Back 38

-collagen type IV
-the glycoprotein laminin
-the glycoprotein fibronectin
-proteoglycan (heparin sulfate)

Front 39

What anchors the basal lamina to the underlying connective tissue?

Back 39

fibronectin, collagen type IV, reticular fibers

Front 40

What attaches the basal lamina to the overlying epithelial cells?

Back 40

laminin

Front 41

The basal lamina prevents ________ and___________ from passing.

Back 41

-negatively charged molecules due to the proteoglycan

-large substances due to the meshwork created by the collagen type IV fibers

Front 42

Integrin, a type of __________, is bound to _________.

Back 42

-integral membrane protein

-laminin

Front 43

In injured epithelium, the ___________ is important because it directs migration of cells along its surface.

Back 43

basal lamina

Front 44

T or F. The basal lamina is found only in epithelial tissue.

Back 44

False

Front 45

The basement membrane is __________ than the basal lamina.

Back 45

thicker

Front 46

Epithelial cell apical surface specializations include..

Back 46

1. microvilli
2. stereocilia
3. glycocalyx (when combined with microvillia, this is the brush border)

Front 47

The main purpose of microvilli is to...

Back 47

increase surface area of the cell

Front 48

Each microvillus has ___________ oriented parallel to its axis, all anchored to a __________ composed of actin and spectrin.

Back 48

-actin-containing microfilaments

-terminal web

(villains have terminal webs to capture their enemies)

Front 49

Microvilli located in the epididymis and cochlea of the inner ear is termed...

Back 49

stereocilia

Front 50

What is the glycocalyx?

Back 50

it's a filamentous fuzzy coat composed of carbohydrate moieties of transmembrane proteins present in the epithelial cell plasma membranes

Front 51

What is the function of the glycocalyx?

Back 51

protection from physical or chemical injury

Front 52

In the kidney's proximal tubule, the layer of microvilli plus the glycocalyx is called the

Back 52

brush border

Front 53

In the intestinal epithelium, the layer of microvilli plus the glycocalyx is called the

Back 53

striated border

Front 54

Which is longer - cilia or microvilli?

Back 54

cilia

Front 55

Define axoneme.

Back 55

the complex of microtubules and associated proteins comprising the core of each cilium. It's the 9 microtubule doublets surrounding the 1 doublet.

Front 56

What is the ciliary dynein?

Back 56

it's the motor protein that walks along the microtubule doublets, causing the cilia to move.

Front 57

What are the basal bodies in relation to cilia?

Back 57

the electron-dense structures of 9 triplets of microtubules into which the cilia insert.

Front 58

How does the cilia move?

Back 58

-effective stroke--cilia stiffens rapidly, causing forward motion
-recovery stroke--cilia recovers by bending

Front 59

What is ciliary dyskinesia and what does it cause clinically?

Back 59

it's when the cilia cannot move in the body. causes chronic respiratory problems and infertility in men

Front 60

Kartagener's syndrome causes a special type of _________________, in which the _____________ are missing. Kartagner's syndrome also causes the unrelated ____________ illness.

Back 60

-ciliary dyskinesia

-ciliary dynein arms

-dextrocardia (flipped heart)

Front 61

Sturgess syndrome causes a special type of _____________, in which __________ are missing.

Back 61

-ciliar dyskinesia

-microtubule doublets

Front 62

Lateral surface folding is important in epithelial cells in order to

Back 62

increase surface area

Front 63

What are the three components of a junctional complex between cells, from apex to base?

Back 63

1. zonula occludens or tight junctions
2. zonula adherens or belt desmosomes
3. macula adherens or spot desmosomes

Front 64

What is another name for tight junctions?

Back 64

zona occludens

Front 65

What do tight junctions do?

Back 65

prevent water-solube molecules from sliding between cells by fusing two cells together at fusion sites. The more fusion sites, the tighter the tight junction.

maintain membrane protein polarity

Front 66

Fusion sites that comprise tight junctions are formed from _____________ proteins contributed by the two adjoining cells.

Back 66

transmembrane junctional proteins

Front 67

Tight junctions serve to maintain _____________________.

Back 67

plasma membrane protein polarity

Front 68

What kind of linker proteins are involved in belt desmosome attachments?

Back 68

Ca2+ dependent transmembrane linker proteins

Front 69

Belt desmosomes are made of dense plaques located intracellularly attached to _____________.

Back 69

actin filaments

Front 70

What are the functions of belt desmosomes?

Back 70

-Holding adjacent cells together
-providing rigidity to the apical portion of the cell

Front 71

Another word for belt desmosomes is...

Back 71

zonula adherens

Front 72

Another word for spot desmosomes is...

Back 72

macula adherens

Front 73

Spot desmosomes appear to be ______________ and function to ____________.

Back 73

-"Spot weld-like"

-help distriubte Shear forces

Front 74

What kind of epithelial cell junction attaches the basal cell membrane to the underlying basal lamina?

Back 74

hemidesmosomes

Front 75

Gap junctions are made up of many ___________.

Back 75

connexons

Front 76

A connexon is a

Back 76

protein hexamer (6 subunits) that permits movement of hydrophilic molecules up to 1500 daltons

Front 77

The turnover rate for cell renewal for small intestine epithelium is ____. Stratified squamous keratinized epithelium: _________. Epithelial cells of the liver: ________.

Back 77

-small intestine: 4 to 6 days
-skin: ~28 days
-liver: years

Front 78

What is hyperplasia and what triggers it in epithelial tissue? Examples?

Back 78

an increase in the number of cells in a tissue. It is triggered by chronic inflammation or irritation

-calluses, psoriasis, hyperplasia of bladder due to chronic inflammation

Front 79

What is metaplasia and what triggers it?

Back 79

a reversible process where epithelial tissue transforms into different epithelial tissue. Triggered by smoking, for example

Front 80

What is dysplasia?

Back 80

a change in the morphology and organization of cells making up a tissue, usually happens to stratified squamous epithelium.

Front 81

In the early stages of cancer, what is observed when studying the epithelial tissue?

Back 81

tissue dysplasia

Front 82

What is carcinoma?

Back 82

malignant tumor arising from epithelial cells

Front 83

What is adenocarcinoma?

Back 83

a malignant tumor arising from glandular epithelium

Front 84

What is the most common type of tumors in adults?

Back 84

adenocarcinoma

Front 85

The terminal web
a) is only found in pseudostratified columnar epithelium
b) supports microvilli actin cores
c) is the area of insertion for cilia
d) represents the intracellular portion of hemidesmosomes

Back 85

b. supports microvilli actin cores

Front 86

A function of belt desmosomes (zonula adherens) is to

a) prevent passage of water-soluble molecules between epithelial cells
b) provide ion channels that cross cell membranes
c) offer a flexible, supportive base for the basal epithelial cells
d) assist in providing some rigidity to the apical portion of surface epithelial cells
e) all of the above

Back 86

d) assist in providing some rigidity to the apical portion of surface epithelial cells

Front 87

Back 87

Front 88

Both exocrine and endocrine cells are of epithelial origin.
a) True
b) False

Back 88

a. true

Front 89

Which epithelium is actually simple, but has some cells whose apical surface does not reach the surface of the epithelium?

Back 89

pseudostratified columnar epithelium